Electric-power system.



PATENTED MAY 30, 1905.

E. WEAVER.

BLEGTRIG POWER SYSTEM.

APPLICATION rum) 0012. 21.1904.

3 SHEETS-BHEET 1.

INVENTOR WITNESSES No. 790,942. PATENTED MAY 30, 1905. J. E. WEAVER.

ELECTRIC! POWER SYSTEM.

APPLICATION rum) 00m. 21.1004.

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Q q 1"? E q i? o Q I s o 9 i 3 O I I o O i I .e T 3 i NWJ WITIIISSISINVIII'OR WWW-um? I No. 790,942. PATENTED MAY 30, 1905.

J. E. WEAVER.

ELECTRIC POWER SYSTEM.

APPLICATION FILED OCT. 21.1904.

3 SHEETS-SHEET 3.

WITNESSES INVENTOR I 2 Wimh mwv zn N 790,942. Patented May 30, 1905.

UNITED STATES PATENT OFFICE.

JAMES E. IVEAVER, OF ALLEGHENY, PENNSYLVANIA, ASSIGNOR TO THE WEAVERELECTRIC FIRE ENGINE COMPANY, OF PITSBURG, PENN- SYLVANIA, A CORPORATIONOF COLORADO.

ELECTRIC-POWER SYSTEM.

SPECIFICATION forming part of Letters Patent No. 790,942, dated May 30,1905.

Application filed October 21, 1904. Serial No. 229,420.

To 7071/07 it Z/ 601106771: inner conemembers 8 of friction-clutches,the

Be it known that I, JAMES E. TEAVER, of outer members 9 of which aresecured to the 5 Allegheny, Allegheny county, Pennsylvania,armature-shaft by a spline connection, which haveinvented a new anduseful Electric-Power allows them to he slid endwise of this shaft.

System, of which the following is a full, clear, The outer clutchmembers are moved into and and exact description, reference being had toout of engagement with the inner clutch memthe accompanying drawings,forming part of hers by means of levers 10, pivoted to brack- 55 thisspecification, in which ets at 11 and actuated by a shaft 12, havingFigure 1 is a top plan view showingmotors right and left handscrew-threads which en- Io arranged and connected in accordance withgage corresponding screw-threads in collars my invention. Fig. 2 is anend elevation of secured to the lovers. The shaftlZis actuated the same.Fig. 3 is a diagrammatic view of by hand-wheel 13, so that byturningthis hand- 60 the connections. Figs. 4, 5, and 6 are diawheel thefriction-clutches may be moved into grams illustrating the differentarrangements or out of engagement to mechanically connect of themultiple-motor arrangement. Fig. 7 or disconnect the motors. Thefrictionis a side elevation of the main switch in two clutches as theyare screwed into engagement positions, and Fig. 8 is a diagrammatic viewwill compensate for a slight variation in the 5 of my double-commutatorcompound-wound speed of the motors at the time when they are machine.mechanically coupled, so that they will be My invention relates to theclass of elecbrought to the same speed and run in tandem, trio-powersystems wherein a plurality of electhus giving the full power of bothmotors on trio motors are employed, and is especially the pump. Byarranging the motors in tan- 7 designed for the use of electric motorsupon dcmI am enabled to use narrow trucks, which portable fire-engines,though the system may especially adapt my fire-engines to the narrow beused in other connections. streets and congested thoroughfares of acity.

The object of my invention is to provide a The motors in the preferredform are new arrangement of motors whereby two motwenty-five-horse-powermotors, each wound tors may be built up to substantially the same forfive hundred volts, the rear motor being speed and then mechanicallycoupled together. a shunt-wound motor, while the front motor 3 In mysystem one motor is preferably peris adouble-commutatorcompound-woundmamanently connected to the pump or other dechine, one end of thearmature being wound vice to be operated and is therefore under the forone hundred and sixty-seven volts and the load at all times, while theother motor may other for three hundred and thirty-three volts. bemechanically connected or disconnected by The advantage of using thiscomrmund-wound 3 5 means of the clutch. machine in connection with thefive-hundred- In the drawings, in which I show a portion voltshunt-wound machine is that the comof a lire-engine constructed inaccordance with pound machine tends to maintain a constant 5 myinvention, 2 is the rear electric motor, current and voltage through theshunt-wound preferably having direct gearing with the machine underdifferent loads. In the com- 4 pump or other device to be driven, asindipound machine a change of load and speed. cated at 3 3. This motor 2is preferably a will change the strength of the series fieldsshunt-wound machine of the inclosed type. m,so that on an increased loadwith decreased 9 Its shaft is provided with pinions 4 at, con speed thestrength of the field will be increased nected by driving-chains 5 withtoothed wheels and the back-voltage effect will be substan- 45 6,loosely mounted upon the shaft of the front tially uniform.

motor 7 This motor? is preferably adouble- A controller of the ordinarystreet-car type commutator machine havingacompound field. is mountedtransversely under the drivers The toothed wheels 6 are provided withthe seat and is operated by the hand-wheel 14..

This hand wheel is spaced ofi into twelve spaces, marked from O to 12,respectively, so that the operator can move the drumcontroller to thesuccessive notches or steps. The electrical connections are illustratedin the general diagram of Fig. 3. In this diagram 15 is a feed-boxhaving two differentsized holes to receive the different-sized plugs 16and 17, carried on the engines and connected to the lines'w and y, whichare respectively the ground-line and the feed-line. The plugs are ofdifferent size in order to prevent the operator from inserting them inthe wrong holes, thereby preventing any change of polarity in insertingthe plugs. The feedline 3 passes to the circuit-breaker a, which isplaced at the right hand of the drivers seat in the form shown, the feedthence extending to the main switch 6. The other line 3/ leads throughthe magnetic blow-out coil 0 and thence to the controller connections inwhich the various developments shown in Figs. 4, 5, and 6 are obtained.The main switch 6 is of a special type, being made with extended bladesset at an angle from the hinged point in such a manner as to insert intwo clips just as main blades are about to leave the two lower clips onthe main part of the switch, as shown in Fig. 7. This construction isused in order to protect the shunt-field, from which there is a veryheavy self-induction or back kick. By connecting these fields (shown atcl and 6) across the two lower clips in the main part of the switch, asshown, and by connecting the two extended clips through a special bankof resistance (shown at f) this self-induced current is thereby divertedand choked by the resistance which holds it down to the point wherethere is no danger of burning out the fields.

During the first four steps or notches of the controller in starting thefive-hundredvolt motor and the three-hundred-and-thirtythree-volt end ofthe compound motor are in multiple series with theone-hundred-andsixty-seven-volt end of the first motor.

In Fig. 4:, g represents the five-hundred-volt machine, it thethree-hundred-and-thirtythree-volt end, and 7c theone-hundred-andsiXty-seven-volt end of the compound motor. The pointsmarked 1, 2, 3, and 4: are resistances in the line leading to themotors. In this position both motors rotate through all the steps, andin these first four steps the one-hundred-and-sixty-sevenvolt end of thecompound machine acts as resistance to assist the line resistance. Asthe wheel is moved through these four steps the motors get under headwayand build up. At the fifth step the connections change to the diagramshown in Fig. 5, which illustrates the steps from 5 to 8. During thesesteps the fivehundred-volt motor is in series with thethreehundred-and-thirty-three-volt end of the other 5 motor, while theone-hundred-and-sixty-seventhe pumps.

volt end is generating counter electromotive force, which tends tooppose the line-current and have a choking effect upon it. This counterelectromotive force or back voltage also acts to reinforce the currentpassing to the five-hundred-volt machine and assists the resistance incontrolling it. The resistance is therefore merely to give a fineradjustment, the rough adjustment being accomplished by changing theconnections, and thereby utilizing the counter electromotive force ofthe one-hundred-and --siXtyse\-'en-volt machine. During the steps 5 to8, as marked on Fig. 5, the compound machine is at full speed and power;but the five-hundred-volt machine has not reached its capacity in speed,although through steps 5 to 8 it is capable of delivering its fullcapacity of twentyfive-horse power. It will be noted that by thepeculiar system of connections used each motor is capable of giving offits full horsepower while the speed is below the normal capacity. At theninth step the connections change to the form shown in Fig. 6. Withthese connections from 9 to 12 the two motors are not mechanicallyconnected, nor are they electrically connected. They work as twoindependent motors on the same line. These last steps are used to buildup a five-hundred-volt motor to its full speed before the two motors aremechanically connected. At the twelfth step the five-hundred-volt motoris brought up to full speed. The motors are then ready for mechanicallyconnecting, and the friction-clutches may then be thrown in. As theclutches are moved into engagement the compound motor, which is movingat a slightly greater speed than the shunt-motor, will be brought downto the speed of the shunt-motor. This decrease of speed in the compoundmotor will increase the strength of its fields, the friction-clutchbeing thrown in gradually to allow the speed to be gradually reduceduntil it is running at the same speed as the shunt-wound machine. Theload is equalized by the mechanical connections, each motor taking itsown share, of the load.

In starting the motors the operator moves the wheel successively throughsteps 1 to 4, giving a slow speed and low pressure on Through theremaining steps the operator can run for an indefinite period at anynotchexcept through steps 9, 10, and 11, which, as before stated, aremerely for building up the motors to the point where they can bemechanically connected to give the full power of the engine. The smallamount of resistance used is of the spool type and is placedlongitudinally of the vehicle in a box 18 underneath the footboard andrunning back below the drivers seat. These spools are arranged parallelto each other. The controller is provided with an annular blow-out ofordinary type; which IIO serves to extinguish any sparking or flashingin the controller.

At the left hand of the drivers seat and over the hand-wheel leis placeda box 18, containing an overload-circuit breaker of ordinary type, whichwill cut off the current from both machines whenever it is increasedbeyond a predetermined point from any cause, such as grounding, shortcircuit, overloads, &c. This box also contains a push-button by i whichthe operator can instantly cut off the current from the line and stopthe motors by merely striking the projecting knob.

The peculiar arrangement of the motors and connections gives an economyin weight, in space, and in current consumption. The weight of theentire electric equipment is about three thousand pounds, whereas withother systems the weight would be largely increased, as would also theamount of resistance used, the amount or space occupied, and currentconsumed and without the advantage of affording large variations inspeed which may be produced by the arrangement shown.

The feeder-boxes are to be provided near the water-plugs in the districtwhere the engine is to be used. This box is under lock and key andcontains the main switch connected to the plug devices to receive theplugs carried on the engine.

The engine is wired throughout for electric lights to provide forinspection of the different parts.

In starting the engine the operator opens the feeder-box, inserts theplugs, closes the main switch and circuit-breaker, and is ready tostart. This may be done in a few seconds while another operator isconnecting the hose. The wheel 14 is then turned through the successivenotches to the point desired, the pumps being arranged at this time sothat they are merely operating in a closed circuit. If high pressure isdesired, the wheel is turned to the twelfth notch and thefriction-clutches then thrown in.

The advantages of my invention result from the peculiar arrangement ofthe electric motors. Vith this arrangement of the electric motors I amenabled to use the full horsepower of both motors by coupling themtogether mechanically, while providing for different speeds with one orboth motors. The system differs from the ordinary street-car system,where the motors are not mechanically connected, and also from themultiplevoltage system in which four motors are used. By my peculiarcombination of the multiplevoltage system with the series-parallelsystem I obtain a better control with a small amount of resistance, sothat the system may be placed upon a vehicle such as a fire-engine. Theresistance is simple to give the finer graduation between the successivesteps.

Many variations may be made in the form and arrangement of the motorsand connections without departing from my invention.

I claim 1. In an electric-power-transmission mechanism, a plurality ofelectric motors, a permanent driving connection between one meter andthe device to be driven, the other motor being a compound-wounddouble-commutator machine, connections for changing the relation betweenthe commutator of the first motor and those of the double-commutatormachine, and a friction-clutch arranged to mechanically couple oruncouple the electric motors; substantially as described.

2. In an electric-p0wer-transmissionmechanism, a plurality of electricmotors, a permanent driving connection between one of the motors and theelement to be driven, means for varying the electrical connections ofsaid motors, and means for mechanically coupling and uncoupling themotors to and from each other; substantially as described.

3. In an electric-power-transmission mechanism, a plurality of electricmotors, one of which is a shunt-wound motor having permanent drivingconnection with the element to be driven, another being a compound-wounddouble-commutator machine, means for mechanically coupling the motors toand uncoupling them from each other, and means for varying theirelectrical connections; substantially as described.

4. In an electric-power-transmission mechanism, a pair of electricmotors arranged in tandem with their shafts in parallelism, a clutchdevice arranged to mechanically couple and uncouple the motors, and apump or element to be driven connected to at least one of said motors;substantially as described.

5. In an electric-p0wer-transmission mechanism, a pair of electricmotors arranged in tandem with their shafts in parallelism, a clutchdevice arranged to mechanically couple and uncouple the motors, and apump or element to be driven connected to one only of said motors;substantially as described.

6. In an electric-power-transmission mechanism, a pump, a plurality ofelectric motors arranged in tandem with their shafts in parallelism, oneof said motors having actuating connections with the pump, and africtionclutch arranged to mechanically couple and uncouple the motorsto and from each other; substantially as described.

7. In an electric-power-transmission mechanism, a plurality of electricmotors, a pump or element to be driven connected to one of said motors,means for building up the motors to drive them at substantially the samespeed, and means for coupling and uncoupling the motors to and from eachother; substantially as described.

8. In an electric-power-transmission mechanism, a plurality of electricmotors, a pump or element to be driven connected to one of said motors,means for building up the motors to drive them at substantially the samespeed, means for coupling and uncoupling the motors to and from eachother, and means for varying the electrical connections of said motors;substantially as described.

9. In an electric-power-transmission mechanism, a pair of motorsarranged in tandem with their axes in parallelism, a pump or element tobe driven having actuating connections with one of said motors, meansfor varying the electrical connections of said motors and building themup to the same speed, and means for mechanically connecting anddisconnecting the motor-shafts; substantially as described.

10. A fire-engine having a plurality of electric motors mounted thereon.one of said motors beinga compound-wound double-commutator machine,pumps having actuating connections with the other motor, and acontroller arranged to place said other motor and one part of thecompound motor in multiple series with the other part of the compoundmotor, and also arranged to connect them as two independent motors onthe same line, substantially as described.

11. A fire engine having a compoundwound double-commutator motor andanother motor, pumps having driving connections with the second motor, acommutator arranged to shift the electric connections and allow theother motor to build up, and means for mechanically coupling up themotors together; substantially as described.

12. A fire-engine having a plurality of electric motors mounted thereon,pumps having driving connections with one of said motors, electricalconnections between the motors, the other motor being a compound-wounddoublecommutator machine, and a controller arranged to shift theelectrical connections for the motor to vary the power, the compoundmotor acting as a booster; substantially as described.

13. A fire-engine having a plurality of electric motors mounted thereon,pumps having actuating connections with one of said motors, the motorsbeing electrically connected, and the second motor having a compoundWinding and a double commutator; substantially as described.

14. An electric engine havingaplurality'of motors, one of which is acompound-Wound double-comm utator machine arranged to act as a booster,resistance arranged to give a finer adjustment between the motors, and adrumcontroller arranged to vary the connections; substantially asdescribed.

15. An electric fire-engine having a plurality of motors, one of whichis mechanically connected with the pump, the other being a compoundwound double commutator machine, connections for changing the relationbetween the commutator of the first motor and those of thedouble-commutator machine, and a clutch device arranged to mechanicallyconnect two motors; substantially as described.

In testimony whereof I have hereunto set my hand.

JAMES E. WEAVER.

Witnesses:

JOHN MILLER, H. M. CoRwIN.

